How long will one load of lump last?

Are you filling the lump up to the fire ring or firebox?

I don't think it matters much.  I prefer Rockwood.

ninnymugs said:

lousubcap said:

Here's a question:  Define for me in more detail "I filled it up before cook with fresh lump" in terms of the interior of your BGE- above the air holes, top of the fire box, top of the ring..."  In other words, you need fuel to run the rig-how much fuel did you start with?  (BTW-size obviously dictates the total quantity you can load in one shot).  

Basically up to top of fire ring. I am using a KAB with the bottom grate still in egg. I’ve always done this, but maybe I shouldn’t?

Your set up is fine.

@XC242 - you must of got a bad batch of Rockwood from @stlcharcoal.  When I burn for more that 6hrs my RW starts to double in size.  I'm still on my 5th bag I bought in 2015.  

Contact @stlcharcoal. He can get you the needed info. 

Lg here and also using RO. Did a 3 butt cook a few weeks ago at 250 for 8 hours and left the egg running until I got some enchiladas done then bumped the temp up to 350 for the enchiladas and some corn. Total time was probably close to 11 hours. Had a little lump left over, two handfuls ish. Question @ninnymugs , is your bag of RO marked USA?? I should probably double check my thermometer calibration too.

All comes down to how many BTU's are in that charcoal.  The lighter / less dense the wood, the less BTU's.  And the less it's kilned, the less BTU's.  Not going to call out brands here, because it really shouldn't matter on burn time if you're filling to the top of the fire ring and running <250F.  Anything should run for at least 18 hrs.  I've gone 30 hrs in my large at 225F, but there's not anything that you would ever smoke that long, so who cares.  With anything, it's going to vary based off the batch, the size of the meat, the outside air temp, and if you're running a water pan.  Egg is pretty good about not carrying about OAT, but I can tell the diff when it's a cold windy (or rainy) night--more charcoal used and the fan on the FB running at a higher % for longer.  Temp controller, chimney, grate type, etc doesn't effect anything.

This was with Wicked Good lump on my large egg. One of the longest cooks I can recall. I think I could have gone at least 25 hours at that temp. And if I had filled it to the top of the fire ring...! I've never really paid attention to how long RO lasted, but I've never run out of either brand (the only two I've ever used) for any temp or duration cook I've done.

Carolina Q said:

This was with Wicked Good lump on my large egg. One of the longest cooks I can recall. I think I could have gone at least 25 hours at that temp. And if I had filled it to the top of the fire ring...! I've never really paid attention to how long RO lasted, but I've never run out of either brand (the only two I've ever used) for any temp or duration cook I've done.

On charcoal made from really dense wood, like Brazilian walnut/cashew/etc, it's going to last longer in a fixed space because it weighs more......similar BTU/#, but more BTU/cu-in.  If you look at the physical bag size between 20# bags at the exact same carbonization, it makes more sense (the dense stuff is going to be a smaller bag.)  But you can't really rely on that because you don't know the carbonization......so it could be the exact opposite of what I just said if it's undercarbonized.

Did I thoroughly confuse everyone yet?

Basically if you're looking at the burn time based off a really dense chunk vs. another similar sized chunk, yes it burns longer, but that's because it weighs more.  And you buy charcoal by weight, so you're buying 20# of BTU's.....about 235,000 of them in a bag of ours (plus the overage.)

Ah, good example......A ream of paper has the same amount of BTU's whether you let it sit flat in the pack, or wadded every piece of paper up into a loose ball.  You can fit the entire ream in the BGE, or probably less than 1/4 of it if you wadded it up or shredded it in to confetti.  The burn time is affected by how much O2 can get to it; but in the end, the BTU/# of that paper is always going to be the exact same for the ream.......which you paid a fixed price for.